I have noticed after eating pineapple that the skin inside my mouth is raw and peeling. what can i do to heal my mouth as it hurts now.

Avoid acids: Avoid acidic food while you are healing. Avoid pineapple specifically.

Raw and peeling: You might be biting your cheeks as an unconscious habit. When you eat acidic or spicy foods it stings the already raw tissue. Try to be more aware of this habit, reduce stress, perhaps with exercise and avoid foods that irritate the tissues. It will heal on its own (unless of course if you keep biting your cheeks).